2-phenacylpyrrolidines are described by R. B. Herbert et al. (J.C.S., Chem. Comm., 1976, 450-451) as intermediates for alkaloids of the septicin type. From U.S. Pat. Nos. 3,931,155 and 3,882,104 1-(aryl-substituted-phenyl)-2-pyrrolidin-2-yl-ethanones and -ethanols (intended to be used as anticoagulants) are known. The properties of certain pyrrolidin-2-yl-ethanones and -ethanols as inhibitors of blood platelet aggregation were investigated by J. M. Grisar et al. [J. Med. Chem., 19 (1976) 1195 to 1201].